The transistor: happy birthday to you
- Branko Brkic
- 23 Dec 2009 11:36 (South Africa)
Without it, you probably wouldn’t be reading this article. In fact, you probably wouldn’t be doing a whole bunch of things you do on a daily basis. So spare a thought for the transistor, whose birthday it is today.
On this day 62 years ago one of the most important inventions of the 20th century, the transistor, was demonstrated at Bell Laboratories in Murray Hill, New Jersey. A semiconductor device that amplifies or switches electric signals, the transistor was developed to replace vacuum tubes, and today is the chief active component in just about every electronic gadget on the market. While a number of companies still produce over a billion individually-packaged transistor units each year, the vast majority occur in integrated circuits – known more commonly as microchips, or simply chips.
Vacuum tubes, the transistor’s predecessor, tended to leak, and the metal they contained that emitted electrons often burned out. Also, the tubes drew on so much power that big and complicated circuits tended to use too much energy to run efficiently. So Bell Labs, AT&T’s research-and-development arm, launched a project to find an alternative.
In the spring of 1945, William Shockley designed what he hoped would be the first semiconductor amplifier, relying on something called the “field effect”. But the device didn’t work, and Shockley recruited experimental physicist Walter Brattain and theoretical physicist John Bardeen to find out why.
Shortly before Christmas in 1947, Bardeen made the breakthrough. Up until that time, no-one understood the true behaviour of electrons in crystals. When Bardeen discovered that electrons form a barrier on the surface of crystals, it took a matter of days for the first point-contact transistor to be built.
Although Shockley was reported to have called the invention “a magnificent Christmas present,” he was furious that he hadn’t been directly involved. Still, he got his revenge – working in a hotel room in Chicago for four intense weeks, he developed a more rugged and practical device than the point-contact transistor. Shockley’s junction transistor, which was also much easier to manufacture, became the central artifact of the electronic age.
Shockley, Bardeen and Brattain would never work together again, but they would jointly receive the 1956 Nobel Prize in Physics “for their researches on semiconductors and their discovery of the transistor effect.”
By staff writer